KR101818002B1 - High Refractive Index Curable Liquid Light Emitting Diode Encapsulant Formulation - Google Patents

Abstract

A polysiloxane prepolymer having a TiO ₂ domain with an average domain size of less than 5 nm and containing 20 to 60 mol% of TiO ₂ (based on total solids) and having a refractive index of> 1.61 to 1.7 and a liquid at room temperature and atmospheric pressure, Curable liquid polysiloxane / TiO ₂ composites for use as light emitting diode encapsulants are provided. A light emitting diode manufacturing assembly is also provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a high refractive index curable liquid light emitting diode encapsulant formulation,

The present invention relates to a photoresist composition comprising a polysiloxane prepolymer of the following average composition formula with a TiO ₂ domain having an average domain size of less than 5 nm, containing 20 to 60 mol% TiO ₂ (based on total solids) and having a refractive index of> 1.61 to 1.7 , A curable liquid polysiloxane / TiO ₂ composite which is liquid at room temperature and atmospheric pressure:

The present invention also relates to a light emitting diode manufacturing assembly.

Light emitting diode (LED) devices typically include an LED die encapsulated in an optically transparent, thermally stable material. The encapsulant generally comprises (1) promoting the introduction of light emitting diodes into the device; (2) to protect the fragile wiring of the light emitting diode; (3) providing at least one of three functions of acting as a refraction moderator between the high-refractive-index die and the low-refractive air. In some LED devices, a preformed plastic lens or glass lens is attached or bonded to the package with the LED die embedded therein. A curable liquid encapsulant is then injected into the cavity between the LED die and the plastic lens (or glass lens) and cured to completely seal the LED die.

There is a tendency to directly mold the curable liquid encapsulant to the LED die using an in-line molding process. In this in-line molding process, the curable liquid encapsulant is injected or potted into the mold cavity containing the LED die (or containing the LED die), followed by curing the encapsulant, which encapsulates the LED die And functions to form a lens for molding the light emitted from the LED die. This in-line molding process omits the process of preassembling and assembling the lens into the LED device. As a result, in-line molding processes ensure a more cost-effective, high-volume manufacture of LED devices.

Thus, high refractive index polymers are useful as lenses and encapsulants for use in light emitting diode device applications. For example, in the manufacture of LED devices, manufacturers require optical polymers that are highly transparent in the visible region, have high refractive indices (i.e., refractive indexes greater than about 1.60), and have good thermal stability over tens of thousands of operating hours. The use of a high refractive index material can significantly improve the light extraction efficiency from the LED die at the same drive current, thus making the LED device more energy efficient. In addition, the LED device industry uses liquid prepolymers, which are then cured in situ after multiple devices have been assembled. Thus, the cured polymer system should exhibit a minimum shrinkage and should be cured under conditions which are not harmful to the assembled device

Commonly used materials for encapsulating LED die include epoxy resin and silicone. Conventional epoxy resins show poor light stability over time (i.e., yellowing over time) after exposure to ultraviolet or high thermal conditions. This yellowing reduces the light output from the LED device over time. On the other hand, conventional silicon exhibits much better heat and light stability. As a result, silicon is used as a main encapsulant in LED devices. However, conventional silicone encapsulants exhibit refractive indices in the range of 1.41 to 1.57 (measured at 550 nm). Moreover, it proved difficult to achieve a refractive index greater than about 1.6 (measured at 550 nm) without significant performance degradation, such as flowability in uncured state.

The refractive index of the encapsulant plays an important role in determining how much light is extracted from the LED device. This is because the light is totally or highly internally reflected as it passes from the solid state high refractive index LED die to the low refractive index polymer medium. The refractive index of a typical LED die is about 2.5. Therefore, it is of great interest to obtain a high refractive index silicone sealant while maintaining the fluidity in the uncured state.

The refractive index of the polymer is determined by the molar refraction of its constituent groups. Commercially available silicone monomers are mainly a combination of an aliphatic group and a phenyl group. This effectively limits the refractive index to the upper limit of 1.57 to 1.58 in conventional curable liquid silicone. The refractive index of poly (diphenylsiloxane) is 1.61, but it is a solid polymer. Since many applications require a liquid prepolymer, it is necessary to reduce the refractive index of the blended material by blending a monomer having a low glass transition temperature (T _g ) with a diphenylsiloxane monomer to obtain a liquid. As mentioned above, the refractive index upper limit is 1.57 to 1.58.

Two approaches have been proposed to improve the refractive index of silicone polymers. One of them is to blend the organopolysiloxane with a refractive index enhancer such as TiO ₂ . The other is to react the silicon precursor with the titanium alkoxide. Nevertheless, the refractive index exhibited by the material was lower than expected due to the non-uniformity of the product produced, and the complexes were difficult to handle (i.e. they were non-uniform and non-flowable).

One group of liquid prepolymers is disclosed by US Patent Application Publication No. 09/0039313 to Conner et al. Corner et al. Described a (thio) phenoxyphenylphenylsilane composition comprising (thio) phenoxyphenylphenylsilane of formula (I)

In this formula,

Ph ¹ is selected from Ph ² -Q-, -Si (Ph ³ ) (OR) ₂ and A phenyl ring having 4 hydrogen atoms as a substituent;

Ph ² -Q is a (thio) phenoxy group, wherein Ph ² is phenyl, Q is selected from an oxygen atom, a sulfur atom, and combinations thereof;

Ph ² -Q is ortho, meta- or para- to the Si atom on the Ph ¹ phenyl ring;

Ph ³ is phenyl;

R is independently selected from a hydrogen atom, a C _1-10 hydrocarbon radical, and combinations thereof; Wherein the C _1-10 hydrocarbon radicals are linear, branched or cyclic C _1-10 alkyl; Phenyl; Substituted phenyl; Arylalkyl; And combinations thereof.

Nevertheless, there is still a need for a transparent high refractive index material for use in the manufacture of light emitting diodes. In particular, there is a need for a light emitting diode encapsulant formulation that forms a curable composition that is high in refractive index, excellent in thermal stability and liquid of transparency, or liquid before, during, or after curing. In many cases, a silicone composite that can be cured with an elastomer is needed. In this case, it is convenient to provide a precursor based on a liquid silicone composite capable of forming a crosslinked and cured composition.

Curable liquid polysiloxane / TiO ₂ composites for use as light emitting diode encapsulants are provided.

The present invention comprises (consisting essentially of) a polysiloxane prepolymer of the following average composition formula with a TiO ₂ domain having an average domain size of less than 5 nm (measured preferably by transmission electron microscopy (TEM)) and comprises from 20 to 60 TiO ₂ composite for use as a light-emitting diode encapsulant comprising a TiO ₂ mol% (based on total solids), a refractive index of> 1.61 to 1.7, and a liquid at room temperature and atmospheric pressure.

In this formula,

Each R < ¹ & R ³ is independently selected from a C _6-10 aryl group and a C _7-20 alkylaryl group;

Each R < ² > is a phenoxyphenyl group;

Each R ⁴ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group;

Each R ⁵ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, a C _6-10 aryl group, and a phenoxyphenyl group;

Each Z is independently selected from a hydroxyl group and a C _1-10 alkoxy group;

0 & lt ; a <0.005;

0.8495 & lt ; b <0.9995;

0.001 & lt ; c <0.10;

0 < d < 0.15;

x is selected from 0, 1 and 2;

y is selected from 1, 2 and 3;

a + b + c + d = 1.

The present invention also includes a polysiloxane prepolymer of the following average composition formula having a TiO ₂ domain having an average domain size of less than 5 nm (preferably measured by a transmission electron microscope (TEM)) and comprising 20 to 60 mol% TiO ₂ of the total based on solids) to be contained, and a refractive index of> 1.61 to 1.7, as a curable liquid polysiloxane / TiO ₂ composite liquid at room temperature and atmospheric pressure, (a) non-protonic (aprotic) solvent, (i) the formula R ¹ ( R ² ) a D unit of Si (OR ⁶ ) ₂ ; (ii) a T unit of the formula R ³ Si (OR ⁷ ) ₃ ; (iii) optionally, M units of the formula R ⁴ ₃ SiOR ^8; And (iv) optionally, combining the Q units of the formula Si (OR ⁹ ) ₄ , wherein each R ⁶ , R ⁷ , R ⁸ and R ⁹ is independently selected from a hydrogen atom, a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group; (b) adding an acid in a miscible mixture of water and alcohol to the combination of (a) to form a reaction mixture; (c) reacting the reaction mixture; (d) adding an organic-titanate in the aprotic solvent to the reacted reaction mixture of (c); (e) adding water to the product of (d); (f) heating and reacting the product of (e); And (g) provides a curable liquid polysiloxane / TiO ₂ composite is prepared in the step of providing a curable liquid polysiloxane / TiO ₂ composite to give the product of (f):

In this formula,

Each R &lt; ¹ & R ³ is independently selected from a C _6-10 aryl group and a C _7-20 alkylaryl group;

Each R &lt; ² &gt; is a phenoxyphenyl group;

Each R ⁴ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group;

Each R ⁵ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, a C _6-10 aryl group, and a phenoxyphenyl group;

Each Z is independently selected from a hydroxyl group and a C _1-10 alkoxy group;

0 & lt ; a &lt;0.005;

0.8495 & lt ; b &lt;0.9995;

0.001 & lt ; c &lt;0.10;

0 < d < 0.15;

x is selected from 0, 1 and 2;

y is selected from 1, 2 and 3;

a + b + c + d = 1.

The present invention also relates to a support structure having a plurality of discrete semiconductor light emitting diode dies; And a mold having a plurality of voids corresponding to the plurality of discrete semiconductor light emitting diode dies; Wherein the plurality of voids are filled with the curable liquid polysiloxane / TiO ₂ composite of the present invention; The support structure and the mold are provided so that the plurality of discrete semiconductor light emitting diode dice are each at least partially immersed in the curable liquid polysiloxane / TiO ₂ composite contained in the plurality of voids.

details

Siloxane polymers are widely used in the electronics industry. For example, siloxane polymers are being used as underfill formulations for light emitting diodes, protective coatings, potting agents, die binders, encapsulants and lenses. However, in many applications in the electronics industry, there are special cases where the polymer is constrained to be used in liquid curable form. That is, in many such applications (e.g., underfill and lens molding), the partially or completely enclosed space is filled with a liquid curable material and then cured. For example, in manufacturing lenses for light emitting diodes, a sealed mold is usually used to form the lens. After the liquid curable material is dispensed or injected into the mold cavity, it is cured. In this molding process, it is desirable to minimize the content of volatile substances in the liquid-curable material used in order to omit the necessity of solvent removal or gasification promotion from the system.

The curable liquid polysiloxane / TiO ₂ composite of the present invention is designed to produce a light emitting diode having a semiconductor light emitting diode die (preferably a plurality of semiconductor light emitting diode dies), wherein the semiconductor light emitting diode die (s) (Preferably, completely encapsulated) within the polysiloxane / TiO ₂ composite. In particular, the curable liquid polysiloxane / TiO ₂ composites of the present invention surprisingly are liquids with minimal (<4 wt%, preferably <2.5 wt%) solvent or solvent (i.e., knit) even with a high TiO ₂ loading rate. The curable liquid polysiloxane / TiO ₂ composite of the present invention also exhibits a high refractive index (> 1.61). This property of the curable liquid polysiloxane / TiO ₂ composite of the present invention makes it ideally suited for use in semiconductor light emitting diodes.

The curable liquid polysiloxane / TiO ₂ composites of the present invention become curable using known methods. Preferably, the curable liquid polysiloxane / TiO ₂ composite is thermoset (preferably heated at 100 to 200 ° C for 10 to 120 minutes).

The curable liquid polysiloxane / TiO ₂ composites of the present invention comprise a polysiloxane prepolymer of the following average composition formula with a TiO ₂ domain having an average domain size of less than 5 nm (preferably < 3 nm) as measured by a transmission electron microscope (TEM) (Preferably consisting essentially of):

[In the above formula,

Each R &lt; ¹ & R ³ is independently selected from a C _6-10 aryl group and a C _7-20 alkylaryl group (preferably R ¹ and R &lt; ³ &gt; are all phenyl groups);

Each R &lt; ^{2 &gt;} is bonded to silicon as a phenoxyphenyl group to form at least one of three different isomers, i.e., an ortho-phenoxyphenylsilane group, a meta-phenoxyphenylsilane group, or a para-phenoxyphenylsilane group;

Each R ⁴ is a C _1-10 alkyl group, C _7-10 arylalkyl group, C _7-10 alkylaryl groups and C _6-10 aryl group (preferably a C _1-5 alkyl group, C _7-10 aryl Group, a C _7-10 alkylaryl group and a phenyl group, more preferably a C _1-5 alkyl group and a phenyl group, most preferably a methyl group and a phenyl group);

Each R ⁵ is a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, a C _6-10 aryl group, and a phenoxyphenyl group (preferably a C _1-5 alkyl group, C _{7 - 10} arylalkyl group, C _7-10 alkylaryl group, a phenyl group and phenoxyphenyl group; more preferably C _1-5 alkyl group, phenyl group and phenoxyphenyl group; most preferably a methyl group, phenyl Group and a phenoxyphenyl group);

Each Z is independently selected from a hydroxyl group and a C _1-10 alkoxy group (preferably a hydroxyl group and a C _1-4 alkoxy group, more preferably a hydroxyl group and a C _1-2 alkoxy group);

0 & lt ; a &lt;0.005;

0.8495 < b < 0.9995 (preferably 0.9 < b < 0.9995, more preferably 0.9 < b < 0.9992, and most preferably 0.95 < b < 0.9992);

0.0005 < c < 0.10 (preferably 0.0008 < c < 0.10, more preferably 0.001 < c < 0.06, most preferably 0.001 < c < 0.02);

0 <d < 0.15 (preferably 0 <d < 0.099, more preferably 0 <d < 0.04, most preferably 0.0005 < d < 0.02);

The curable liquid polysiloxane / TiO ₂ composite comprises 20 to 60 mol% TiO ₂ (based on total solids) (preferably 20 to 58 mol%, more preferably 30 to 58 mol%, most preferably 50 to 58 mol% );

Each x is independently selected from 0, 1 and 2 (i.e., x may be the same or different for each R ⁵ _x Z _y SiO _{(4-xy) / 2} group contained in the prepolymer);

The angle is independently selected from 1, 2 and 3 (i.e., y may be the same or different for each R ⁵ _x Z _y SiO _{(4-xy) / 2} group contained in the prepolymer);

a + b + c + d = 1;

The curable liquid polysiloxane / TiO ₂ composite is liquid at room temperature and atmospheric pressure.

Preferably, the refractive index of the curable liquid polysiloxane / TiO ₂ composite of the present invention is> 1.61 to 1.7, more preferably 1.63 to 1.66, and most preferably 1.64 to 1.66. Preferably, the viscosity of the curable liquid polysiloxane / TiO ₂ composite of the present invention is <600,000 Pa * s, more preferably 4 to 100,000 Pa * s, most preferably 4 to 20,000 Pa * s, s. Preferably, the curable liquid polysiloxane / TiO ₂ composite of the present invention is thermosetting, and optionally a catalyst is added.

Preferably, the curable liquid polysiloxane / TiO ₂ composite of the present invention comprises (i) a D unit (preferably 84.95 to 99.95 mol%) of the formula R ¹ (R ² ) Si (OR ⁶ ) _{2 in} an aprotic solvent, , More preferably 90 to 99.95 mol%, still more preferably 90 to 99.92 mol%, most preferably 95 to 99.92 mol% D unit); (ii) the general formula R _³ Si (OR ^{7) 3} in the T units (preferably 0.05 to 10 mol%, more preferably from 0.08 to 10 mol%, still more preferably 0.1 to 6 mol%, and most preferably 0.1 to 2 mol% T units); (iii) optionally, units of the formula R ⁴ ₃ SiOR ⁸ M (preferably 0 to 0.5 mol% M units); And, (iv) optionally, the formula Si (OR ⁹⁾ to the ₄ Q unit (preferably 0 to 15 mol%, more preferably 0 to 9.9 mol%, even more preferably from 0 to 4 mol%, and most preferably 0.05 to 2 mol% Q units), wherein each of R &lt; ^{1 &gt;} and R &lt; R ³ is independently selected from a C _6-10 aryl group and a C _7-20 alkylaryl group (preferably R ¹ and R &lt; ³ &gt; are all phenyl groups); Each R &lt; ^{2 &gt;} is bonded to silicon as a phenoxyphenyl group to form at least one of three different isomers, i.e., an ortho-phenoxyphenylsilane group, a meta-phenoxyphenylsilane group, or a para-phenoxyphenylsilane group; Each R ⁴ is a C _1-10 alkyl group, C _7-10 arylalkyl group, C _7-10 alkylaryl groups and C _6-10 aryl group (preferably a C _1-5 alkyl group, C _7-10 aryl Group, a C _7-10 alkylaryl group and a phenyl group, more preferably a C _1-5 alkyl group and a phenyl group, most preferably a methyl group and a phenyl group); Each R ^6, R ^7, R ^8, and R ⁹ represents a hydrogen atom, a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group (preferably a hydrogen atom and a C _1-5 alkyl group; Hydrogen and a methyl group, most preferably a methyl group); (b) adding to the combination of (a) an acid in a miscible mixture of water and an alcohol (preferably a _C1-8 alkyl hydroxide, more preferably methanol, ethanol, propanol, butanol) More preferably inorganic acids selected from hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, hydrofluoric acid and hydrobromic acid, even more preferably hydrochloric acid, nitric acid and sulfuric acid, most preferably hydrochloric acid) , More preferably dropwise while maintaining the temperature at 0 to 80 캜, and most preferably, while keeping the temperature at 15 to 70 캜) to form a reaction mixture; (c) reacting the reaction mixture (preferably while maintaining the reaction mixture at a temperature of from 0 to 80 캜; more preferably, maintaining the reaction mixture at a temperature of from 15 to 70 캜); (d) adding to the reaction mixture of (c) the organic-titanate in the aprotic solvent (preferably, the dropwise addition, more preferably the dropwise while maintaining the temperature at 30 to 100 ° C, Keeping the temperature at &lt; RTI ID = 0.0 &gt; 70 C &lt; / RTI &gt; (e) adding water (preferably, dropwise, more preferably dropwise while maintaining the temperature at 30 to 100 占 폚, most preferably maintaining the temperature at 70 占 폚) to the product of (d); (f) heating and reacting the product of (e) to form a curable liquid polysiloxane / TiO ₂ composite (preferably, the product of (e) is heated to a temperature of > 60 ° C, more preferably 60 to 150 ° C heating); (g) purifying the product of (f) to provide a curable liquid polysiloxane / TiO ₂ composite (preferably, the curable liquid polysiloxane / TiO ₂ composite contains 20 to 60 mol% TiO ₂ (based on total solids)) .

(f), the formation of the curable liquid polysiloxane / TiO ₂ complex also results in the formation of by-products such as ethanol, methanol, isopropanol and water. These by-products are advantageously removed from the curable liquid polysiloxane / TiO ₂ composite in (g). Preferably, these by-products are removed from the curable liquid polysiloxane / TiO ₂ composite by at least one of distillation and rotary evaporation in (g). Optionally, extraction solvents can be used to aid in the removal of these by-products. Examples of extraction solvents include _C5-12 linear, branched and cyclic alkanes (e.g., hexane, heptane, and cyclohexane); Ethers (e.g., tetrahydrofuran, dioxane, ethylene glycol diether ether, and ethylene glycol dimethyl ether); Ketones (e.g., methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone); Esters (e.g., butyl acetate, ethyl lactate and propylene glycol methyl ether acetate); Halogenated solvents (e.g., trichloroethane, bromobenzene, and chlorobenzene); Silicone solvents (e.g., octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane); And combinations thereof.

Preferably, the D units used in the preparation of the curable liquid polysiloxane / TiO ₂ composite have the formula:

In this formula,

Each R ⁶ is independently selected from hydrogen and C _1-4 alkyl groups (more preferably, each R ⁶ is a methyl group).

Preferably, the T units used in the preparation of the curable liquid polysiloxane / TiO ₂ composite have the formula:

In this formula,

Each R ⁷ is independently selected from hydrogen and C _1-4 alkyl groups (more preferably, each R ⁷ is a methyl group).

Preferably, the acid used in the preparation of the curable liquid polysiloxane / TiO ₂ composite is selected from Bronsted acid (for example, acetic acid, formic acid, propionic acid, citric acid, hydrochloric acid, sulfuric acid and phosphoric acid). More preferably, the acid used is selected from acetic acid and hydrochloric acid. Most preferably, the acid used is hydrochloric acid.

Preferably, the curable liquid polysiloxane / organic complex used in the production of TiO _2-titanate (R ¹⁰ O) of the formula The organic _{e Ti f O (f-1} ) - titanate [where each R ¹⁰ is C _{1- 20} alkyl group, a C _6-10 aryl group, a C _7-20 alkylaryl group, and a C _7-20 arylalkyl group; f is selected from 1, 2, 3, 4 and 5; and e is 2 * (f + 1). More preferably, the organo-titanate is tetraethyl titanate; Tetraisopropyl titanate; Tetra-n-propyl titanate; Tetra-n-butyl titanate; Tetraisooctyl titanate; Tetraisostearoyl titanate; Tetraoctyleneglycol titanate; Ethane bis (pentane-2,4-dione-0,0 ') propane-2-olato) titanium and titanium tetrabutanolate polymers. Most preferably, the organo-titanate is titanium tetra-butanol methacrylate polymer (e.g., Tyzor ^® BTP that is commercially available from DuPont).

Preferably, the purity of the curable liquid polysiloxane / TiO ₂ composite of the present invention is > 95 wt% (more preferably & gt ; 98 wt%). Preferably, the raw materials used in the preparation of the curable liquid polysiloxane / TiO ₂ composites of the present invention are purified to increase the purity of the curable liquid polysiloxane / TiO ₂ composite product. The raw materials used can be purified by, for example, distillation, chromatography, solvent extraction, membrane separation and other conventional purification methods.

The curable liquid polysiloxane / TiO ₂ composite optionally comprises an inert diluent; Reactive diluent; Steric hindrance amine light stabilizers (HALS); Lubricating additives; Fungicide; Flame retardant; Contrast enhancer; UV-stabilizers; Light stabilizer; Surfactants; An adhesion modifier; Rheology modifiers; Phosphorescent material; Absorbing dyes; Fluorescent dyes; Electrical or thermal conductive additives; Chelating or quenching agents; Acid scavenger; Base scavenger; Metal passivators; And metal reinforcements. &Lt; Desc / Clms Page number 7 &gt;

The light emitting diode manufacturing assembly of the present invention includes a support structure having a plurality of discrete semiconductor light emitting diode dies; And a mold having a plurality of voids corresponding to the plurality of discrete semiconductor light emitting diode dies; Wherein the plurality of voids are filled with the curable liquid polysiloxane / TiO ₂ composite of the present invention; The support structure and the mold are oriented such that the plurality of discrete semiconductor light emitting diode dice each are at least partially immersed in the curable liquid polysiloxane / TiO ₂ composite contained in the plurality of voids. Preferably, each pore in the plurality of pores is in the form of a lens. Preferably, the curable liquid polysiloxane / TiO ₂ composite is thermally curable (more preferably, the curable liquid polysiloxane / TiO ₂ composite cures upon heating at 100-200 ° C for 10-120 minutes). Preferably, the curable liquid polysiloxane / TiO ₂ composite encapsulates the discrete semiconductor light emitting diode die upon curing and performs both functions as a lens. The mold optionally further comprises a plurality of supply channels that facilitate the injection of the curable liquid polysiloxane / TiO ₂ composite into the plurality of voids.

The light emitting diode manufacturing assemblies of the present invention facilitate the manufacture of manifolds comprising a plurality of discrete semiconductor light emitting dies, for example, designed for use in automotive headlight assemblies. On the other hand, the light emitting diode fabrication assembly of the present invention facilitates the fabrication of discrete semiconductor light emitting diodes. That is, after the curing of the curable liquid polysiloxane / TiO ₂ composite, the mold is separated from the assembly, and then a plurality of discrete semiconductor light emitting diode dies encapsulated with the cured curable polysiloxane / TiO ₂ composite on the substrate are diced into discrete semiconductor light emitting diodes dice).

Hereinafter, some embodiments of the present invention will be described in detail in the following examples.

The siloxane monomer of the formula is referred to as "POP" in the following examples:

The POP monomers used in the following examples were prepared in the same manner as in Example 1. &Lt; / RTI &gt;

Siloxane monomers of the following formula are referred to as PTMS in the following examples, which are available from Gelest Inc.:

Example 1 Preparation of POP Monomer

To a 500 mL Schlenk flask was added diethyl ether (400 mL); Magnesium metal powder (3.3 g; 135 mmol); And methyl iodide (0.1 mL). Then, the flask was further charged with 4-bromodiphenyl ether (32.161 g; 129 mmol), and the reaction mixture was stirred for 4 hours. Phenyltrimethoxysilane (25.601 g, 129 mmol) was added to the flask and the contents stirred for 1 hour. The contents of the flask were transferred to a 1 L separatory funnel and the material was washed twice with 400 mL distilled water. The ether layer was collected and the volatiles were removed under reduced pressure. And further purification by distillation disconnecting the purity of the crude product was> to give the POP monomer product of 97% purity. POP monomer product contained phenoxyphenyl halide in <500 ppm.

Comparative Examples A and 2-4

Curable liquid polysiloxane / TiO ₂  Manufacture of composites

Curable liquid polysiloxane / TiO ₂ composites were prepared according to the following general method using the specified amounts given in Table 1. Specifically, the amount of POP and PTMS given in Table 1 was added to a 100 mL three-neck round bottom flask with 13.2 g of propylene glycol methyl ether acetate (PGMEA). A solution of 5.0 g of methanol, 1.0 g of water and 0.16 g of concentrated hydrochloric acid (37% in water, obtained from Fisher Scientific) was added dropwise to the flask. The contents of the flask were then heated to 70 DEG C and maintained at that temperature for 1.5 hours with a constant temperature heated mantle equipped with a heating probe and a reflux condenser. The amount of titanium tetra-butanol acrylate polymer (commercially available as Tyzor ^® BTP from DuPont) as given in Table 1 was dissolved in PGMEA of 8.8 g, the flask contents to a flask of dry tetrahydrofuran (THF) in 1 mL through the addition funnel Was added dropwise over 1 hour while maintaining the temperature at 70 占 폚. Water (0.1 mL) and PGMEA (4.4 g) were added to the flask. The contents of the flask were heated to 100 占 폚 and reacted for 1 hour. The volatiles were then distilled in a flask equipped with a single distillation column. After rotary evaporation, a high vacuum (25 mTorr) was applied at 60 ° C to remove volatiles from the flask contents. From the flask, The optically clear curable liquid polysiloxane / TiO ₂ composite, the product of 2-4, was recovered. compare The reaction described in Example A yielded a milky white two-phase mixture, indicating that colloidal TiO ₂ particles were formed and aggregated.

Example No. POP
(g) PTMS
(g) Tyzor ^® BPT
(g) POP
(mol%) ^ζ PTMS
(mol%) ^ζ TiO ₂
(mol%) ^η A 3.4 0.106 5.45 95 5 67 2 5.9 0.212 4.54 94 6 49.1 3 5.9 0.212 5.45 94 6 53.7 4 3.4 0.106 0.83 95 5 23.6

^ζ Based on the total number of moles of siloxane monomer (POP + PTMS)

^η two Siloxane monomers (POP + PTMS) and Tyzor ^® of equimolar amounts induced by BPT introduced, based on the total molar number of the sum of TiO ₂ (i.e., TiO ₂ 3 moles for each mole of Tyzor ^® BPT).

Comparative Example B and Examples 5-8

Curable liquid polysiloxane / TiO ₂  Manufacture of composites

Curable liquid polysiloxane / TiO ₂ composites were prepared according to the following general method using the specified amounts given in Table 2. Specifically, the amount of POP and PTMS given in Table 2 was added to a 100 mL three-neck round bottom flask with 6.6 g propylene glycol methyl ether acetate (PGMEA). A solution of 2.5 g methanol, 0.5 g water and 0.08 g concentrated hydrochloric acid (37% in water, obtained from Fisher Scientific) was added dropwise to the flask. The contents of the flask were then heated to 70 DEG C and maintained at that temperature for 1.5 hours with a constant temperature heated mantle equipped with a heating probe and a reflux condenser. Was dissolved in a given amount of titanium tetra-butanol acrylate polymer (commercially available as Tyzor ^® BTP from DuPont) in PGMEA of 4.4 g in Table 2, the contents of the flask into the flask through the addition funnel in anhydrous tetrahydrofuran (THF) in 0.5 mL Was added dropwise over 1 hour while maintaining the temperature at 70 占 폚. Water (0.05 mL) and PGMEA (2.2 g) were added to the flask. The contents of the flask were heated to 100 占 폚 and reacted for 1 hour. The volatiles were then distilled in a flask equipped with a single distillation column. After rotary evaporation, a high vacuum (25 mTorr) was applied at 60 ° C to remove volatiles from the flask contents. The product of the optically clear curable liquid polysiloxane / TiO ₂ composite from the flask was recovered.

Example No. POP
(g) PTMS
(g) Tyzor ^® BPT
(g) POP
(mol%) ^ζ PTMS
(mol%)  ^ζ TiO ₂
(mol%) ^η B 2.9 0.085 0 95 5 0 5 2.9 0.106 1.36 94 6 37 6 2.95 0.018 2.63 99 One 54 7 2.9 0.02 0.7 99 One 24 8 3.1 0.21 3.05 90 10 24

^ζ Based on the total number of moles of siloxane monomer (POP + PTMS)

^η two Siloxane monomers (POP + PTMS) and Tyzor ^® of equimolar amounts induced by BPT introduced, based on the total molar number of the sum of TiO ₂ (i.e., TiO ₂ 3 moles for each mole of Tyzor ^® BPT).

Examples 9-12: Curable liquid polysiloxane / TiO ₂  Manufacture of composites

Curable liquid polysiloxane / TiO ₂ composites were prepared according to the following general method using the specified amounts given in Table 3. Specifically, the amount of POP and PTMS given in Table 3 was added to a 100 mL three-neck round bottom flask with 15 mL of propylene glycol methyl ether acetate (PGMEA). A solution of 5 g methanol, 1 g water and 0.16 g concentrated hydrochloric acid (37% in water, obtained from Fisher Scientific) was added dropwise to the flask. The contents of the flask were then heated to 70 DEG C and maintained at that temperature for 1.5 hours with a constant temperature heated mantle equipped with a heating probe and a reflux condenser. Table 3 Amount of titanium tetra-butanol acrylate polymer (commercially available as Tyzor ^® BTP from DuPont) given on was dissolved in PGMEA in 10 mL, of the flask contents to a flask of anhydrous tetrahydrofuran (THF) in 1 mL through the addition funnel Was added dropwise over 1 hour while maintaining the temperature at 70 占 폚. Water (0.1 mL) and PGMEA (5 mL) were added to the flask. The contents of the flask were heated to 100 占 폚 and reacted for 1 hour. The volatiles were further removed from the contents of the flask by rotary evaporation at 60 ° C under high vacuum. The product of the optically clear curable liquid polysiloxane / TiO ₂ composite from the flask was recovered.

Example No. POP
(g) PTMS
(g) Tyzor ^®
BPT
(g) POP
(mol%) ^ζ PTMS
(mol%) ^ζ TiO ₂
(mol%) ^η 9 5.907 0.0035 ^ψ 5.465 99.9 0.1 55.3 10 5.911 0.0175 5.450 99.5 0.5 55.0 11 5.902 0.108 5.472 97.0 3.0 54.6 12 5.905 0.224 5.460 94.0 6.0 53.7

4.7 [mu] l of [ ^psi] PTMS material was added to a solution containing about 0.0035 g of monomer.

^ζ Based on the total number of moles of siloxane monomer (POP + PTMS)

^η two Siloxane monomers (POP + PTMS) and Tyzor ^® of equimolar amounts induced by BPT introduced, based on the total molar number of the sum of TiO ₂ (i.e., TiO ₂ 3 moles for each mole of Tyzor ^® BPT).

Comparative Example C-D

Composites were prepared according to the following general method using the specific amounts given in Table 4. Specifically, the amount of POP monomer given in Table 4 was added to a 100 mL three-neck round bottom flask with 6.6 g propylene glycol methyl ether acetate (PGMEA). A solution of 2.5 g methanol, 0.5 g water and 0.08 g concentrated hydrochloric acid (37% in water, obtained from Fisher Scientific) was added dropwise to the flask. The contents of the flask were then heated to 70 DEG C and maintained at that temperature for 1.5 hours with a constant temperature heated mantle equipped with a heating probe and a reflux condenser. The amount of titanium tetra-butanol acrylate polymer (commercially available as Tyzor ^® BTP from DuPont) as given in Table 4 were dissolved in PGMEA of 4.4 g, the contents of the flask into the flask through the addition funnel in anhydrous tetrahydrofuran (THF) in 0.5 mL Was added dropwise over 1 hour while maintaining the temperature at 70 占 폚. Water (0.05 mL) and PGMEA (2.2 g) were added to the flask. The contents of the flask were heated to 100 占 폚 and reacted for 1 hour. The products obtained in each of Comparative Examples C and D were milky white and completely opaque, indicating that colloidal TiO ₂ particles were formed and aggregated.

Example No. POP
(g) Tyzor ^® BPT
(g) TiO ₂
(mol%) ^η C 2.9 0.7 24.4 D 2.9 2.6 54.5

Based on the moles of equimolar amounts of TiO ₂ induced by introduction of ^η POP and Tyzor ^® BPT (ie, 3 moles of TiO ₂ for each mole of Tyzor ^® BPT).

Comparative Example E: one-step preparation

Dissolving in 6.6 g of propylene glycol methyl ether acetate (PGMEA) POP (2.9 g) and PTMS (0.09 g) and, 4.4 g of PGMEA and was Tyzor dissolved in anhydrous tetrahydrofuran (THF) in 0.5 mL ^® BTP (0.72 g) were charged to a 100 mL round bottom flask. Then, a solution of 2.5 g methanol, 0.5 g water and 0.08 g concentrated hydrochloric acid (37% in water, obtained from Fisher Scientific) was added dropwise to the flask. The contents of the flask were then heated to 70 DEG C and maintained at that temperature for 1.5 hours with a constant temperature heated mantle equipped with a heating probe and a reflux condenser. The product obtained was milky white and completely opaque, indicating that colloidal TiO ₂ particles were formed and aggregated.

Comparative Examples VA and VC-VE, and Examples V2-V11

The viscosities of the respective products from Comparative Examples A and CE and Examples 2-11 were measured using a Rheometrics Mechanical (trade name, manufactured by New Metals, Delaware), Rheometric Scientific Inc. (now TA Instruments Inc.) Were evaluated according to the following procedure using Spectrometer (RMS-800) in Comparative Examples VA and VC-VE and in Examples V2-V11, respectively. Specifically, in each case, a sample of the material to be tested was loaded on two aluminum parallel plates 8 mm in diameter and sandwiched. The meter fixture and plate were preheated to 60 占 폚 and equilibrated at this temperature for 15 minutes before the interplanar gap became zero. Thereafter, the temperature of the parallel plate was raised to 90 DEG C to facilitate loading of the liquid sample having a viscosity exceeding 100 Pa-s. After loading the sample material onto the bottom plate, the instrument was placed on the HOLD until the oven was backcooled to 60 ° C. The sample gap was adjusted to 0.5 mm. Extra samples pushed to the edge of the parallel plate during the gap setting of the samples loaded on the bottom plate were trimmed with a spatula. Subsequently, when the temperature reached equilibrium (after about 15 minutes), the sample gap from the instrument was recorded in micrometers. The dynamic frequency sweep was initiated at a radial stress range of 100 rad / s to 0.1 rad / s in the linear viscoelastic range. The shear viscosity of the composite was recorded as a function of frequency. Viscosity data at 60 ° C and 10 rad / s are shown in Table 5, demonstrating that the material of each sample can flow relatively easily.

Example Test substance Viscosity (Pa · s) VA  Product of A solid VC Product of C Not measured (NM), the product of C is 2 phase VD Product of D The product of NM, D is 2-phase AND The product of E The product of NM, E is 2-phase V2 The product of Example 2 8.1 x 10 ⁴ V3 The product of Example 3 5.2 x 10 ⁵ V4  The product of Example 4 4.2 V5 The product of Example 5 1.4 x 10 ² V6 The product of Example 6 1.4 x 10 ³ V7 The product of Example 7 7.8 V8 The product of Example 8 29 V9 The product of Example 9 6.8 x 10 ⁴ V10 The product of Example 10 1.1 x 10 ⁴ V11 The product of Example 11 8.2 x 10 ³

Comparative Example RB and Example R2-R12: Refractive index

The refractive indices of the products of Comparative Example B and Examples 2-12 were determined by visual observation in a sodium D-line using an Atago digital refractometer (model: RX-7000 alpha) in Comparative Example RB and Example R2-R12, respectively Respectively. The results are shown in Table 6.

Example Test substance RI (at 589 nm) RB The product of B 1.608 R2 The product of Example 2 1.641 R3 The product of Example 3 1.650 R4 The product of Example 4 1.621 R5 The product of Example 5 1.637 R6 The product of Example 6 1.648 R7 The product of Example 7 1.632 R8 The product of Example 8 1.635 R9 The product of Example 9 1.651 R10 The product of Example 10 1.648 R11 The product of Example 11 1.650 R12 The product of Example 12 1.650

Example S3

Example In the curable liquid polysiloxane / TiO ₂ composite prepared according to the TiO ₂ 3 Average domain size, operating at 200 keV and Bruker XFlash ^® 5030 SDD silicon drift energy dispersive x- ray detector equipped with a JEOL 2010F field emission transmission electron microscope using And it was measured by transmission electron microscopy (TEM) to be about 3 nm.

Example S9

Example The average TiO ₂ domain size in the curable liquid polysiloxane / TiO ₂ composites prepared according to Example 9 was measured using a JEOL JEM 1230 transmission electron microscope operating at 100 keV accelerating voltage, a Gatan 791 and Gatan 794 digital camera And after post-processing the image using Adobe Photoshop 7.0, it was <5 nm.

Examples C9-C12

Examples C9-C12 In Examples 9-12 were thermally cured samples of the curable liquid polysiloxane / TiO ₂ composite prepared according to each, respectively. In each of Examples C9-C12, it was placed curable liquid polysiloxane / TiO ₂ 1 hour a sample of the composite material to 120 ℃ convection oven. In each of the examples C9-C12, the composite material which was initially liquid was fully cured to a rigid solid after heat treatment in a convection oven.

Claims (10)

A polysiloxane prepolymer of the following average composition formula with a TiO ₂ domain having an average domain size of less than 5 nm, containing 20 to 60 mol% TiO ₂ (based on total solids), having a refractive index of> 1.61 to 1.7, Curable liquid polysiloxane / TiO ₂ complex for use as a light emitting diode encapsulant, liquid at atmospheric pressure:

In this formula,
Each R < ¹ & R ³ is independently selected from a C _6-10 aryl group and a C _7-20 alkylaryl group;
Each R < ² &gt; is a phenoxyphenyl group;
Each R ⁴ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group;
Each R ⁵ is independently selected from a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, a C _6-10 aryl group, and a phenoxyphenyl group;
Each Z is independently selected from a hydroxyl group and a C _1-10 alkoxy group;
0 & lt ; a &lt;0.005;
0.8495 & lt ; b &lt;0.9995;
0.0005 & lt ; c &lt;0.10;
0 &lt; d &lt; 0.15;
Each x is independently selected from 0, 1, and 2;
Each y is independently selected from 1, 2, and 3;
a + b + c + d = 1. The method according to claim 1,
(a) in an aprotic solvent
(i) a D unit of the formula R ¹ (R ² ) Si (OR ⁶ ) ₂ ;
(ii) a T unit of the formula R ³ Si (OR ⁷ ) ₃ ;
(iii) optionally, M units of the formula R ⁴ ₃ SiOR ^8; And
(iv) optionally, a Q unit of the formula Si (OR ⁹ ) ₄
, Wherein each R &lt; ⁶ &gt;, R &lt; ⁷ &gt;, R &lt; ⁸ & R ⁹ is independently selected from a hydrogen atom, a C _1-10 alkyl group, a C _7-10 arylalkyl group, a C _7-10 alkylaryl group, and a C _6-10 aryl group;
(b) adding an acid in a miscible mixture of water and alcohol to the combination of (a) to form a reaction mixture;
(c) reacting the reaction mixture;
(d) adding an organic-titanate in the aprotic solvent to the reacted reaction mixture of (c);
(e) adding water to the product of (d);
(f) heating and reacting the product of (e); And
(g) purifying the product of (f) to provide a curable liquid polysiloxane / TiO ₂ composite;
Lt; _{RTI ID = 0.0} &gt; polysiloxane / TiO2 &lt; / RTI &gt; 2 wherein, the supplied curable liquid polysiloxane / TiO curable liquid polysiloxane / TiO ₂ composite purity is 95 wt% of the composite _2. The curable liquid polysiloxane / TiO ₂ complex according to claim 3, wherein the D unit has the following formula:

In this formula,
Each R ⁶ is independently selected from hydrogen and C _1-4 alkyl groups. The method of claim 4, wherein each R ⁶ is methyl group, the curable liquid polysiloxane / TiO ₂ composite. 5. The curable liquid polysiloxane / TiO ₂ complex of claim 4 wherein the T units have the formula:

In this formula,
Each R ⁷ is independently selected from hydrogen and a C _1-4 alkyl group. The curable liquid polysiloxane / TiO ₂ complex of claim 6, wherein each R ⁷ is a methyl group. A support structure having a plurality of discrete semiconductor light emitting diode dies; And
A mold having a plurality of voids corresponding to a plurality of discrete semiconductor light emitting diode die;
Wherein the plurality of voids are filled with the curable liquid polysiloxane / TiO ₂ composite of claim ₁ ;
The support structure and the mold are arranged such that the plurality of discrete semiconductor light emitting diode dies each are oriented so as to be at least partially immersed in the curable liquid polysiloxane / TiO ₂ composite contained in the plurality of voids,
Light emitting diode manufacturing assembly. 9. The assembly of claim 8, wherein the cavity is in the form of a lens. The method of claim 8, wherein the mold is a light emitting diode manufacturing assembly further comprises a plurality of supply channels to facilitate injection of the curable liquid polysiloxane / TiO ₂ composite of a plurality of pores.